Trommelmag 101?

[SIGP2101]

I've had this repro for about 30 years and never really fooled with it other than clean and oil.....like much of my stuff. I actually like it since it fits my 30 cal and holds 7 rounds. It will not, however, fit my 9mm Erfurt...sticks about half way in. So, the question is were originals made for different calibers? Then, with regard to the 'holster', how were they carried? The repro case has 2 short straps, don't know if that was standard.

Here:

http://forum.lugerforum.com/attachme...4&d=1356112513